Difference between Individual Electric Drive and Group Drive System

Individual Electric Drive

In an electric drive system, if an individual machine is fitted with its own motor and each operator has complete control on their machine, then it is termed as an individual electric drive.

Examples − Drill machine, lath machine, etc.

Group Drive System

A group drive system uses a high powered motor to drive a common shaft. When several machines are organized on a single shaft and are driven by a single large motor, this system is known as group drive. Group drive is also known as line shaft drive because a large sized motor (called main motor) drives a common shaft. To the common shaft, a number of small machines are connected by means of multi-stepped pulleys.

Examples − Food grinding mills, paper mills, etc.

The following figure shows the block diagram of group drive.

Comparison between Individual Drive and Group Drive

The following table compares and contrasts the different features of individual electric drive and group electric drive −

Point of Comparison
Individual Drive
Group Drive
Motor required
Separate motor is required to drive each individual machine.
One single motor is required to drive a common shaft.
Total power required in H.P.
As each machine requires a separate motor. Thus, the total sum of powers (in HPs) is more.
As it needs only a single motor, thus the total power in HP required for complete section is lesser.
Overload capacity
The individual drive system has less overload capacity.
The group drive system has high overload capacity.
The operation of individual drive is safe.
The operation of group drive is not safe.
Speed control
In individual drive, the speed of each motor can be controlled separately.
In group drive, the speed control of individual machine is not possible.
System Appearance
The individual drive system has clean appearance.
The group drive system has clumsy appearance.
The layout of individual drive can be changed, i.e. a new machine can be installed as per requirement and space available.
The layout of group drive is fixed and cannot be changed.
In individual drive more separate machines can be added in future.
In case of group drive, future extensions are not possible.
Effect of fault
Fault in one machine does not disturb operation of other machines.
Fault in the main motor drive stops operation of all machines.
Power loss
Individual drives have less power losses.
Power losses are more in the group drives.
Cost involved in individual drive is much more.
For group drive, the cost is much less.
Individual drives are used in lifts, cranes, shapers, lath machines, etc.
Group drives are used in workshops, paper mills, textile mills, etc.